Ventlri tube



y 1935. c. JUSTHEIM Re. 19,581

VENTURI TUBE Original Filed Jan. 11, 1954 Reissues] Ms, 21, 1935 UNI-TEDSTATES VENTUBI TUBE Clarence I. Justhelm, Salt Lake Clty, Utah OrlginalNo. 1,973,714. dated September 18, 1934, Serial No. 706.308, January 11,1934. Applicammm. m n. ma.

1 Claims; (c1; zen-a2) My invention relates to Venturi or auction tubesand has for its object to provide a new and emcient suction tube whichmay be used to create suction in any desired place, such as upon aero- 5planes for actuating their wind instruments, on

automobiles to gauge wind resistances when traveling, or to actuate thespeedometer oi the automobile, or tobe used in the suction device formixing fuel and air for carburetion of the fuel for the engine.

A further object is to provide a suction device which has the interiorform so designed that it will accomplish the best'results obtainablewith a suction tube'either when used with gas or fluids.

A still further object is to provide a suction Venturi tube for drawingfluids therethrough to increase the suction in the ports thereof, thedesign being such as to create the greatest suction obtainable with thistype of device.

These objects I accomplish with the device illustrated in theaccompanying drawing in which similar numerals and letters of referenceindicate like parts throughout the several views and asdescribed in thespecification forming a part of this application and pointed out in theappended claims In'the drawing in which-I have shown the device Figure 1is a diagrammatic view to illustrate the proper manner of laying out thedesign forthe tube with the correct and most eflicient angles of flareused therein.

Figure 2 is a diametrical section of the device showing the use of onlyone suction port.

Figure 3 is a diametrical section of the device showing the use of aring of ports through the device into an annular ring, to create suctionin the ring, and thereby from the device to which the lead line from thering is attached.

This application is a segregation of portions of the patent applicationflied by me on February 2, 1932, Serial Number 590,493, for Suction andvaporizing devices.

In the drawing I have shown the device as made of opposed frusto-conlcalchambers A and B Joined together by a curved wall C with the angles offlare and the diameters and radii flgured out to give the most eflicientdevice possible.

In Figure l, the diagrammatic view, the mannerofbuiidingthedeviceisshown. TheflareA is made by first laying out thewalls thereof with a predetermined flare. This tube is preferably eightinches long with an internal diameter at thesmallendFoflinch.Atthesmallendoi'the iiaredtubeAJthenlayoflalinecperpendicu- Serial No.

lartothewallland thenusingaradiusequal to the diameter of the small end,I then scribe the curved wall C. With the line a as a base, I

then erect a perpendicular line b thereto, the base of the line startingat the center of the curve. 5 At the juncture of this line b to thecurved wall C, I form the walls I of an opposed flare chamber B. Thewall 2 of the chamber 13 is joined to the curved wall C at a point whichwill not be tangential to the curve, and the small end of the chamber31s or larger diameter than the am end of the chamber A.

- The larger diametered tube B is made of a. length to provide sumcientdistance from the entrance thereinto, to the curved wallsC, to pro- 15duce the desired suction for the tube, so that this distance whenmeasured will be greater than the inner diameter of the small end of thechamber A where it Joins the curved wall. This is a shorter distance asshown in the drawing than the length of the standard short tube whenconsidering the diameter of the entrance of the tube B; as shown inthedrawing, when this length is sufflcient for the-fluids to engage thewalls of the tube B after having made their usual entrance arc therein,this length will then increase the efliclency of the device.

In order to retain the volumetric efliciency of the tube, severalvariables have to be taken into consideration when designing it. Thesevariables are approximately as follows: angles oi convergence anddivergence of frustumsB and A respectively; construction of curve C tothe lesser diametered frustum A and the length of the frustum B ascompared to the diameter of the constriction F.

It is a well known fact that the quantity of gas or liquid which passesthe constriction F will be equal to the area or cross section at Fmultiplied by the velocity.

It is also a fact that the velocity past any point in the tube is themedium for producing the suction at this particular point. That is,should a tube connected to fuel, be inserted at this point a certainsuction acts upon it. As the velocity past this point is the factor forproducing the suction on the inserted tube and the velocity at thisparticular point in the frustum depends upon its distance from theentrance of the frustum B, the length of the frustum B is a definitefactor in the design of the conical converging tube B when consideringthe combination of B, C and A.

In Figure 2 of the drawing a port I leads into the interior of thedevice at that juncture of the curvedwallCtothechamberAatthepoint.atwhichtheinnerwalllotthechamberais tangential to the inner wall 4 orthe curve C. The port is formed or bored through the wall with the axisthereof in alignment with the junc- 5 tureoithecurvedwalltotheflaredwalllbut' slight variation may be made withoutdeparting from the efllciency oi the device to any great degree.

InFigure3 otthe device theiuncture o! thecurvedwalltothechamberAissurroundedby' an annular chamber I formed oftwo halves secured together to form the completed chamber and theinterior of the chamber l'isin connection with the interior oirthedevice by the row 15 otportslboredthroughthewalllottheflared chamber Alat the tangential juncture of the curved wall 8 to the wall I. A leadline l draws from any suitable or desired source or creates suction inany instrument to which the device may be attached.

. An arrow 1: shows the direction of travel of fluids through thedevice.

In using this venturi tube as a carburetor suitable control valves mustbe provided to control the suction through the device. and these valvesmay be mounted at either end of the suction device or at both ends it sodesired.

Through experimentation, the following table was worked out for theflared chamber B to show the various results using. diflerent flares,thus showing, that the best angle of flare is that described. a

0.61s 0. ma asst The contraction coeflicients were then deduced from Cl-0+6.

The method or obtaining the coefllcient oi velocity makes no allowancefor the retardation 'oi the particles in the chamber B by theatmosphere; hence'the coefllcients may be a little small, and thecontraction coefllcients would then be too large,'-as deduced from theabove equation.

This would seem to account for the value 1.001, as seen in the secondcolumn.

Relativetothechambergthechieilossot head in the standardshort tube isoccasioned by .the sudden enlargement or the contracted veintoflllthetullsectionoithetube. Thus thecurve Co!chamberaistormedwiththewalls tofltthe curve otthe. fluid inordertoobtainthe greatest 'efllciency.

Having thus described my invention, I desire to secure by Letters Patentand claim:

1'. 1!: a Venturi tube, the combination of opposed irusto-conicalaxially aligned chambers Joined together by a'curved wall with thechamber into which the fluid is introduced of largerdiameterthantheotherchamber,andwiththe smaller chamber tangential to thecurved wall.

2. In a Venturi tube, the combination of a flared chamber having thesmall end Joined onto an inwardly curved wall; another flared chamberjoined onto the endo! the curved wall with the walls thereot tangentialto the curve; and a port through the tangential juncture of the curvedwall -to the flared chamber.

3. In a device of the class described, the combination of airusto-conical chamber Joined to an opposed trusto-cenical chamber by acurved wall with the smaller diametered chamber Joined to the curvedwall so that the walls are tangential to the curve; a row or annularports through the tangential juncture of the chamber to the curved wall;a. chamber surrounding said row of ports; and a suction line from saidchamber.

- 4. In a venturi tube of the class described, the combination of air'usto-conical chamber Joined to an opposed smaller diameteredirusto-conical chamber by a curved wall with the smaller diameteredchamber tangential to the curved wall; ports into the interior oi! theVenturi tube; an

annular chamber surrounding said ports; and:

a suction line connected with said annular chamber. i

5. In a Venturi tube the combination of a flared chamber having thesmall end joined onto an inwardly curved wall with the length-01 thechamber greater than the inner diameter or the curved wall: anotherflared chamber Joined onto I theend oi'thecurvedwallwiththewallsthereo!tangential to the curved wall.

6. In a Venturi tube the combination of opposed irusto-conical axiallyaligned chambers Joined together by a curved wall with the chamber intowhich the fluid is introduced 0! larger diameter than the other chamberand of greater length than the diameter of the juncture of the curvedwall portion with the smaller chamber tangential to the curved wall. 5

7. In a Venturi tube the combination or a trusto-conical chamber joinedto an opposed i'rusto;-- conical chamber of larger diameter by a curvedwall with the radii of the curved wall on lines Perpendicular tothevwall ot the smaller diametered chamber at the juncture with thecurved CLARENCE I. JU

